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/* -------------------------------------------------------------- */ /* (C)Copyright 2001,2008, */ /* International Business Machines Corporation, */ /* Sony Computer Entertainment, Incorporated, */ /* Toshiba Corporation, */ /* */ /* All Rights Reserved. */ /* */ /* Redistribution and use in source and binary forms, with or */ /* without modification, are permitted provided that the */ /* following conditions are met: */ /* */ /* - Redistributions of source code must retain the above copyright*/ /* notice, this list of conditions and the following disclaimer. */ /* */ /* - Redistributions in binary form must reproduce the above */ /* copyright notice, this list of conditions and the following */ /* disclaimer in the documentation and/or other materials */ /* provided with the distribution. */ /* */ /* - Neither the name of IBM Corporation nor the names of its */ /* contributors may be used to endorse or promote products */ /* derived from this software without specific prior written */ /* permission. */ /* */ /* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND */ /* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, */ /* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */ /* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE */ /* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR */ /* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */ /* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT */ /* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; */ /* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) */ /* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */ /* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR */ /* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */ /* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* -------------------------------------------------------------- */ /* PROLOG END TAG zYx */ #ifdef __SPU__ #ifndef _ASINF4_H_ #define _ASINF4_H_ 1 #include <spu_intrinsics.h> #include "divf4.h" #include "sqrtf4.h" /* * FUNCTION * vector float _asinf4(vector float x) * * DESCRIPTION * The _asinf4 function computes the arc sine for a vector of values x; * that is the values whose sine is x. Results are undefined if x is * outside the range [-1, 1]. * */ static __inline vector float _asinf4(vector float x) { /* The arcsin is computed using two different algorithms, depending * upon the absolute value of the input. For inputs in the range * [0, PI/4], it is computed as the ratio of two polynomials. * * asin(x) = p/q; * * where p = P11*x^11 + P09*x^9 + P07*x^7 + P05*x^5 + P03*x3 + x * q = Q08*x^8 + Q06*x^6 + Q04*x^4 + Q02*x^2 + Q00 * * For the range of value [PI/4, 1], the arcsin is computed using: * * asin = PI/2 - sqrt(1 - x) * r; * * where r = C07*x^7 + C06*x^6 + C05*x^5 + C04*x^4 + C03*x^3 + C02*x^2 * C01*x + C00; */ vector float r, r1, r2, r_hi, r_lo; vector float xabs, x2, x4, x6; vector float p, p_hi, p_lo; vector float q, q_hi, q_lo; vector float pi_over_2 = spu_splats(1.5707963267949f); vector float pi_over_4 = spu_splats(0.7853981633974f); vector unsigned int msb = spu_splats(0x80000000); x2 = spu_mul(x, x); x4 = spu_mul(x2, x2); x6 = spu_mul(x4, x2); xabs = spu_andc(x, (vector float)msb); /* Compute arc-sin for values in the range [0, PI/4] */ p_hi = spu_madd(spu_splats(0.0000347933107596021167570f), x2, spu_splats(0.000791534994289814532176f)); p_hi = spu_madd(p_hi, x2, spu_splats(-0.0400555345006794114027f)); p_lo = spu_madd(spu_splats(0.201212532134862925881f), x2, spu_splats(-0.325565818622400915405f)); p_lo = spu_madd(p_lo, x2, spu_splats(0.166666666666666657415f)); p = spu_madd(p_hi, x6, p_lo); q_hi = spu_madd(spu_splats(0.0770381505559019352791f), x2, spu_splats(-0.688283971605453293030f)); q_hi = spu_madd(q_hi, x2, spu_splats(2.02094576023350569471f)); q_lo = spu_madd(spu_splats(-2.40339491173441421878f), x2, spu_splats(1.0f)); q = spu_madd(q_hi, x4, q_lo); r1 = spu_madd(_divf4(p, q), spu_mul(xabs, x2), xabs); /* Compute arc-sin for values in the range [PI/4, 1] */ r_hi = spu_madd(spu_splats(-0.0012624911f), xabs, spu_splats(0.0066700901f)); r_hi = spu_madd(r_hi, xabs, spu_splats(-0.0170881256f)); r_hi = spu_madd(r_hi, xabs, spu_splats(0.0308918810f)); r_lo = spu_madd(spu_splats(-0.0501743046f), xabs, spu_splats(0.0889789874f)); r_lo = spu_madd(r_lo, xabs, spu_splats(-0.2145988016f)); r_lo = spu_madd(r_lo, xabs, pi_over_2); r = spu_madd(r_hi, x4, r_lo); r2 = spu_nmsub(r, _sqrtf4(spu_sub(spu_splats(1.0f), xabs)), pi_over_2); /* Select the result depending upon the input value. Correct the * sign of the result. */ return (spu_sel(spu_sel(r1, r2, spu_cmpgt(xabs, pi_over_4)), x, msb)); } #endif /* _ASINF4_H_ */ #endif /* __SPU__ */